JPH08282887A - Fluid support roll and fluid support device for strip - Google Patents

Abstract

PURPOSE: To provide a fluid support roll and a fluid support device which has a mechanism capable of easily selecting a proper nozzle space to plate width or selecting fluid floating carrying and roll carrying, and also can suppress a thermal crown generated at roll carrying. CONSTITUTION: In this fluid support roll for strip, a roll 10 for winding a strip on a roll and carrying and supporting it is formed of a central roll 1 and end rolls 2 provided on both ends thereof and capable of sliding in the roll axial direction, and the end rolls are slid in the roll axial direction, whereby a pair of fluid injection nozzles 4 variable in opening width extending over the whole circumference of the roll are formed spirally in the roll axial direction on the roll surface between the central roll and the end rolls. Further, a highly heat conductive metal member is desirably integrated to the surface of the roll or near the surface. The fluid support roll, a back surface pad and a fluid nozzle are juxtaposed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll for floatingly supporting a running strip by means of a fluid force over the entire strip processing line. More specifically, the present invention relates to a continuous annealing line for steel strips, a continuous plating line, a roll and a device for floating and supporting the strips by a fluid force in the continuous coating line.

Since the present invention can be applied to the production and transportation of other metals, paper, plastics, etc.,
In the following description, it is simply referred to as "strip".

[0003]

2. Description of the Related Art As a method of floating and supporting a strip in a non-contact manner, a method of arranging a large number of fluid bearings and a method of applying the principle of hovercraft are generally known.

In the case of utilizing a fluid bearing, a large number of nozzle holes are arranged on the outer peripheral surface of a drum around which a strip is wound, high-pressure fluid is ejected from these nozzles, and the strip wound around the nozzle is in a non-contact state. This is a method of floating, supporting and transporting.

According to this method, when the strip is floated by air, if the tension of the strip is increased, a very large air pressure is required, and the swing of the strip is said to be large.

Therefore, it is used for transporting light-weight strips such as photographic film, photographic paper, and magnetic tape which do not require a large fluid jetting force as disclosed in JP-A-62-167162. . However, since this method levitates the strip with the ejection energy from a large number of air bearings, when applied to the levitation-supported transport of metal strips, there are too many nozzle holes and a large fluid ejection pressure is required. It is uneconomical.

On the other hand, the one to which the principle of the hovercraft is applied utilizes the cushion pressure generated in the region surrounded by the curtain of the fluid by ejecting the fluid from the slit nozzle toward the inside of the strip to be floated and conveyed. This method also basically converts the kinetic energy of the fluid into static pressure or dynamic pressure to support the strip in a floating manner.

For example, as disclosed in Japanese Unexamined Patent Publication No. 62-139832, it is generally constructed as a fixed type strip levitation device. However, when the strip is conveyed by this method, power is required to continuously supply the fluid, and in order to reduce the running cost, when conveying the strip that does not require floating conveyance, it should be conveyed by rolls. However, since it is a fixed type, it is not possible to use different transportation methods. Furthermore, even in the plate threading work at the tip of the strip, a problem arises only with the levitation transport device.

On the other hand, the inventors of the present invention have disclosed in Japanese Patent Laid-Open No. 571571/1992.
A fluid support device disclosed in Japanese Patent No. 21 has been proposed, in which an auxiliary roll is installed to avoid the complication of switching between levitation transfer and roll transfer and to easily switch the transfer.

However, the fluid support device also has the following points to be improved.

When a fluid is supplied from a plurality of nozzles extending in the circumferential direction of the roll in the plate width direction to form a fluid cushion, the nozzle intervals are set to be wider than the plate width so that the nozzle positions can be arranged inside the plate width. Need to be small. Moreover, if the nozzle spacing is too small relative to the plate width, the cushion becomes unstable, so there is an allowable nozzle spacing for a certain plate width. However, since the plate width to be manufactured is not constant in a normal thin plate processing line, it is necessary to arrange nozzles extending in multiple circumferential directions and select the nozzle to be used according to the plate width. However, when many nozzles are arranged,
The number of movable parts of the roll increases, and a mechanism for selecting the facing nozzle interval according to the plate width is also required, which complicates the structure.

Further, if there is a temperature difference between the strip and the roll, heat is transferred from one to the other, so that a thermal crown is generated in the roll. For example, if the temperature of the strip is higher than the ambient temperature where the roll is installed,
At the strip passing position, heat transfer from the strip raises the roll surface temperature. This temperature difference is conducted by heat conduction in the axial direction and the radial direction of the roll to generate a thermal gradient in the roll. That is, thermal expansion differs depending on the axial position of the roll due to this temperature difference, and appears as a convex crown. On the contrary, when the plate temperature is relatively low, a concave crown occurs. The change in the crown shape of the roll induces the meandering of the strip during traveling and impairs stable traveling.

On the other hand, Japanese Patent Laid-Open No. 63-258354 discloses a method of rotating a roll in order to prevent the deformation of the apparatus due to unbalanced heat during floating transportation of the strip. No technique has been shown that can cope with the suppression of the thermal crown during transportation.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid-supporting roll and a fluid of a simple mechanism which can select an appropriate nozzle interval with respect to a plate width and can easily select fluid levitation transfer and roll transfer. A support device is provided.
Another object of the present invention is to provide a fluid-supporting roll and a fluid-supporting device that suppress a thermal crown generated due to a temperature difference between the roll and the strip when the roll is conveyed.

[0015]

The present inventors have completed the present invention by obtaining the following findings as a result of examining the above problems.

For turning a strip at an angle of 90 degrees,
A fluid cushion can be formed on the roll surface if the circumferential nozzles are arranged on the surface corresponding to an angle of at least 90 degrees with respect to the entire circumference of the roll surface. That is, it is sufficient that the nozzle width corresponds to the strip width within the winding angle range of the strip to be conveyed, and the nozzle width does not have to correspond to the strip width over the entire circumference of the roll. Further, since the distance between the pair of nozzles has a certain degree of freedom with respect to the strip width, it is not necessary to have a constant width parallel to the strip winding surface.

Therefore, a pair of nozzles are spirally formed in the roll axial direction so that the nozzle width formed in the circumferential direction of the roll continuously changes in the circumferential direction of the roll. By selecting the position in the roll circumferential direction that is the nozzle interval of, it is possible to make the device with a simple roll structure.

By simplifying the pair of left and right circumferential nozzles, it is possible to simplify the opening and closing mechanism for the circumferential nozzles for selecting the fluid floating conveyance and the roll conveyance.

In order to prevent the thermal crown due to the temperature difference between the strip and the roll, it is important to mitigate the thermal gradient, and by incorporating an auxiliary medium for promoting heat transfer in the axial direction on the roll surface or in the roll. It is possible to suppress the crown.

From the above, the gist of the present invention is as follows.
A roll for winding and carrying a strip around a roll, the roll comprising a central roll and end rolls provided at both ends and slidable in the roll axial direction, by sliding the end rolls in the roll axial direction. A strip-type fluid-supporting roll having a structure in which a pair of fluid ejection nozzles with variable opening widths are formed spirally in the roll axial direction on the roll surface between a central roll and an end roll.

Further, on or near the surface of the roll,
It is desirable to incorporate a high thermal conductivity metal member so that when the central roll and the end rolls are brought together they will connect in the axial direction of the rolls.

As another aspect, the above roll,
It is a fluid support device for a strip in which a back surface pad is provided so as to face the roll surface opposite to the strip winding surface of the roll, and a fluid nozzle is arranged side by side in the vicinity of the roll winding start line of the strip.

[0023]

The present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view of a fluid support roll of the present invention in which a fluid ejection nozzle at the time of floating conveyance is opened.

FIG. 2 is a front view of the fluid support roll in which the fluid ejection nozzle is closed when it is used as a normal roll of the present invention.

A fluid support roll 10 is formed by a central roll 1 for winding and carrying a strip and end rolls 2 provided at both ends of the roll. The central roll 1 and the end rolls 2 are separated from each other in the axial direction of the roll. As a result, a fluid ejection nozzle 4 (hereinafter, referred to as a "nozzle") that serves as a nozzle is formed on the roll surface. A pair of nozzles 4 are spirally provided in the roll axial direction over the entire circumference of the roll, and the positions thereof are preferably symmetrical with respect to the center of the strip passing position.

The nozzle 4 can change the nozzle opening width t by sliding the end roll 2 on the roll shaft 3, and can function as a normal roll by closing the nozzle as shown in FIG. Is possible.

FIG. 3 is a sectional view of the roll with the nozzle corresponding to FIG. 1 in the open state, and FIG. 4 is a sectional view of the roll with the nozzle corresponding to FIG. 2 in the closed state. The roll shaft 3 is hollow so that a fluid can flow inside, and the central roll 1
A plurality of fluid holes 6 are formed in the roll shaft portion 3 so that the fluid can be fed into the space 5 formed between the end roll 2 and the end roll 2.

FIG. 5 and FIG. 6 are sectional views of another roll of the invention in which the nozzle is open and the nozzle is closed.

In this figure, a high heat conductive metal member 7 made of a metal material having high heat conductivity is incorporated near the surface inside the roll, and when the roll is closed as shown in FIG. 6, it is incorporated in the central roll 1. The high thermal conductive metal member 7 and the high thermal conductive metal member 7 incorporated in the end roll 2 are connected. Therefore, for example, it is possible to suppress the generation of the thermal crown of the roll by efficiently moving the heat generated at the central portion to the low heat portion at the end portion. Further, the same effect can be obtained by incorporating the high thermal conductive metal member 7 into the roll outer surface instead of incorporating the high thermal conductive metal member 7 into the roll as shown in FIGS.

The material of the roll main body and the high thermal conductive metal member is not particularly limited, but the roll is required to have strength as a structure in order to support the tension of the strip. Therefore, it is preferable to use a roll made of steel or stainless steel and use copper, aluminum, silver, or the like as the high thermal conductive metal member. Further, when an austenitic stainless steel material is used for the roll and a copper material is used for the heat transfer member, there is an advantage that the difference in linear expansion coefficient is small, and a combination thereof is suitable. Furthermore, it is preferable that the high thermal conductive metal member and the roll are joined by diffusion joining, shrink fitting, welding or the like, but not particularly limited thereto.

(1) When a Strip is Float-Conveyed FIG. 7 is a side view showing an example of the fluid support device of the present invention for floating-conveying a strip. Fluid support device 2 of the present invention
In No. 0, a fluid nozzle 11 is arranged in the vicinity of the roll winding start line of the fluid support roll 10 and the strips before and after it, and a back pad 15 is provided so as to face the roll surface opposite to the strip winding surface of the roll. It is composed.

FIG. 8 is a view showing an example of the fluid nozzle,
(A) shows the perspective view, (b) shows sectional drawing. The fluid nozzle 11 is provided with a fluid supply pipe 12 and a slit 13 for ejecting fluid toward the strip.

For floating transportation of the strip, the fluid is individually supplied to the fluid support roll 10 and the fluid nozzle 11. First, the right and left fluids individually supplied from the roll shaft 3 travel through the cavities in the roll shaft into the inside of the roll, pass through the fluid holes 6, and then are formed between the central roll 1 and the end rolls 2. It is ejected from the nozzle 4 through the open space 5. At this time, the ejection of the fluid from the lower surface is suppressed by the back pad 15.

On the other hand, the fluid is supplied from the supply pipe 12 to the fluid nozzles 11 arranged on the inlet side and the outlet side of the roll, and is discharged from the slit 13. The ejection angle θ of the fluid from the slit 13 shown in the sectional view of FIG.
45 degrees is desirable.

As described above, by ejecting the fluid from the fluid supporting roll 10 and the fluid nozzle 11, a stable cushion layer of the fluid is formed on the winding surface of the strip, and the strip is floated and supported without contacting the roll. To be done.

Next, the nozzle width Wn (a pair of nozzle intervals) Wn of the fluid support roll 10 shown in FIG. 1 may be appropriately set in advance by focusing on the width of the main strip to be conveyed. The concept of selection will be described below.

In the present invention, the nozzles extending in the roll circumferential direction are spirally provided in the roll axial direction, and the nozzle width Wn continuously changes in the roll circumferential direction. Therefore, the nozzle width Wn can be instantly changed to an appropriate nozzle width Wn by rotating the roll shaft forward or backward in accordance with the width change of the wound strip.

FIG. 9 is a development view of the roll surface for explaining the positional relationship of nozzles formed on the roll surface.

The nozzle width is selected such that the maximum nozzle width Wn is Wn so that the nozzle width Wn is narrower than the strip width W manufactured in a line using the fluid support roll 10.
(max), when the maximum width of the strip is Wmax: Wmax> Wn (max) Also, when the minimum width of the nozzle: Wn (min) and the minimum width of the strip: Wmin, Wmin> Wn (min) select.

Further, the width of the nozzle spirally formed on the roll surface is changed from Wn (max) to Wn (min) in one turn. That is, based on the maximum plate width Wmax and the minimum plate width Wmin, the maximum nozzle width W in the roll axis direction is obtained.
n (max) roll circumferential direction position and minimum nozzle width Wn (m
in), where P is the difference in roll circumferential position, P =
Forming a spiral nozzle of (Wmax-Wmin) / 2 in the roll circumferential direction is a criterion for nozzle design.

When the winding angle of the strip is 90 degrees, Wmin> (Wn (max) / 4) + (3 × Wn (min) / 4) is set. This is a condition that when the winding surface is 90 degrees, the nozzle width becomes narrower than the strip width even at the minimum strip width, and the above formula must be satisfied in determining the spiral shape of the nozzle.

FIG. 10 is a development view of the roll surface for explaining another example of the positional relationship of the nozzles formed on the roll surface.

This will also be described in the case of 90 degree winding,
Only the roll surface that conveys the strip with the minimum width may have parallel nozzle shapes so that the nozzle width is narrower than the minimum width Wmin of the strip, and the other roll surfaces may have a spiral nozzle shape.

Further, the fluid support roll 10 of the present invention is
By sliding the end roll 2 on the roll shaft 3, the opening width t of the nozzle 4 can be arbitrarily set.
Since the ejection speed of the fluid changes depending on the opening width, it is possible to adjust the flying height by adjusting the opening width. Further, the preferable opening width is 2 to 5 mm.

Further, the ejection angle of the fluid from the nozzle 4 is
A range of 30 to 90 degrees towards the central roll is preferred.

(2) In the case of carrying rolls The fluid support roll 10 of the present invention closes the opening of the nozzle 4 by sliding the end rolls 2 provided at both ends of the roll on the roll shaft 3 to close the opening. It can function as a roll. FIG. 4 shows a state in which the end roll 2 is slid and the nozzle 4 is closed when roll transport is performed.
Further, as shown in FIG. 6, in the case of another invention, the high thermal conductive metal member 7 inside the roll is formed by closing the nozzle 4.
Stick to each other.

At a place where a temperature difference does not occur between the strip and the fluid support roll, the roll structure without the heat transfer member shown in FIG. 4 of the present invention may be used. However, in a line where a temperature difference occurs between the fluid-supporting roll and the strip, for example, when a high-temperature strip is wound around the roll, the temperature at the strip passing position rises and a thermal crown is formed. However, by adopting the structure in which the high thermal conductive metal member 7 is incorporated inside the roll as shown in FIG. 6, the heat transfer in the axial direction of the roll is promoted, and the temperature of the portion where the metal material having good thermal conductivity is provided. Tend to be uniform.

When the strip has a high temperature, a convex crown is generated on the roll, but when the cold strip passes through the roll installed in a high temperature atmosphere, the shape of the roll becomes a concave crown, which induces meandering. . In the case of the roll incorporating the high thermal conductive metal member of the present invention, since the mechanism for uniforming the temperature distribution in the axial direction is the same, the generation of the concave crown is suppressed and the threading is stabilized.

FIG. 11 shows another example of the present invention, in which a partition plate 8 is arranged between the central roll 1 and the end roll 2.
The use of a heat transfer member for the partition plate 8 has the effect of increasing the heat transfer surface and contributes to temperature uniformity. In addition, when the surface is floated by the fluid, there is a rectifying effect of radially ejecting the fluid.

[0051]

【Example】

(Embodiment 1) FIG. 12 shows a transfer model line used for confirming the effects of the present invention.

The coil whose temperature has been raised in the heating furnace 21 is discharged, and the strip plate is conveyed through the bridle device 22 to the fluid support device 20 according to the present invention having the structure shown in FIG. 7, and the winding angle of the strip becomes 90 degrees. I did it. Then, it was wound around a tension reel 24 through a tension measuring roll 23. Table 1 shows the specifications of the fluid support roll and the fluid nozzle of the example of the present invention.

[0053]

[Table 1]

In the model line of FIG. 12, the thickness was changed to four types of 0.15 mm thickness and 280 mm, 330 mm, 380 mm and 430 mm.
Using SPCC steel strip as a test material, compressed air was supplied to the fluid support roll and fluid nozzle at room temperature without heating the strip, and the strip was floated and transported at a line speed of 200 m / min.

The amount of air supplied was 25 N / mm ² with a total flow rate of 25 including the fluid support roll and the fluid nozzle.
It was Nm ³ / min. Further, when the materials having the above four kinds of strip widths were conveyed, the roll shaft was rotated so that the nozzle width was narrower than each strip width, and the roll surface to be the winding surface was selected. The nozzle opening width of the fluid support roll was fixed at 2 mm. However, the flow rate balance of each nozzle is adjusted so that the levitation is uniform.

FIG. 13 shows the measurement results of the flying height in the strip width direction. The flying height of the strip was measured with an eddy current sensor.

From FIG. 13, it was possible to carry out stable and uniform floating transportation by the apparatus using the fluid support roll and the fluid nozzle of the present invention. Furthermore, although the levitation support was evaluated with a strip width other than the above strip width, strip levitation with a maximum width of 500 mm was possible.

Next, the strip was heated to 350 ° C. in a heating furnace, and a strip roll test was conducted. The roll used in the test was obtained by closing the roll nozzle shown in Table 1,
As a high thermal conductive metal member, a roll in which copper was incorporated in the vicinity of the roll surface and a roll in which copper was not incorporated were compared. In both cases, the temperature of the strip at the time it was wrapped around the roll was 330 ° C. The roll was run at 230 m / min for about 10 minutes, and after the temperature of the roll was sufficiently increased, the profile of the roll was measured.

FIG. 14 is a diagram showing changes in the amount of thermal crown in the strip width direction.

The sarl crown amount was measured by sliding a contact type dial gauge in the roll axial direction. When using a fluid-supporting roll that does not incorporate copper shown by the solid line, the temperature at the position where the strip is threaded rises, and the difference in the crown amount between the center and the end in the roll width direction is 0.29 mm. A convex thermal crown is generated. On the other hand, when copper is incorporated, the heat is transferred to the end side as shown by the broken line, so the roll surface temperature rises slightly as a whole, but the thermal crown amount is 0.06 mm due to the difference between the central part and the end part. Compared to a roll that does not incorporate copper,
It has been reduced to 5.

Furthermore, when a fluid-supporting roll incorporating copper was used, formation of a convex crown on the roll was suppressed, so that flatness of the strip did not occur.
On the other hand, in the case of a roll in which copper is not incorporated, the contact state between the strip and the roll is not uniform due to the generation of crown, and the flatness failure occurs due to the influence of uneven pulling due to the convex crown.

From this, it was confirmed that when there is a difference in temperature between the strip and the roll, the effect of suppressing the thermal crown is great by incorporating the high thermal conductive metal member into the roll.

(Example 2) A test was conducted using air as a fluid and a fluid support device having the structure shown in FIG. 7 as an alternative to the top roll of the hot dip coating line.

The roll dimensions are 1800 mm in diameter and 2200 mm in body length.
The nozzle width on the roll surface is 1530 to 530 mm, and the structure is such that a pair of spiral nozzles whose nozzle width changes continuously is formed on the surface, and in the circumferential direction between the central roll and the end rolls shown in FIG. Twelve copper partition plates were placed on the. 0.6 ~
A 1.6 mm thick × 800 to 1800 mm wide strip was floated and conveyed while appropriately selecting the nozzle interval. As a result, it was confirmed that the strip after hot-dip galvanizing could be stably floated at a flying height of about 15 mm.

Further, the roll was conveyed with the nozzles closed, but it was possible to pass the roll without causing any flaw in the nozzle portion formed on the roll surface.

[0066]

According to the present invention, it is possible to provide a simple roll structure capable of stably floating and transporting a strip and immediately setting an appropriate nozzle interval for a change in plate width. Further, it has a great effect that the roll can be conveyed and the trouble of passing the plate due to the thermal crown, which is a concern when there is a temperature difference between the roll and the strip, can be avoided.

[Brief description of drawings]

FIG. 1 is a front view of a fluid support roll in a nozzle opening state according to the present invention.

FIG. 2 is a front view of the fluid support roll of the present invention in a nozzle closed state.

FIG. 3 is a cross-sectional view of the fluid support roll in the nozzle opening state of FIG.

4 is a cross-sectional view of the fluid support roll in the nozzle closed state of FIG.

5 is a cross-sectional view of the fluid support roll when the high thermal conductive metal member is incorporated in the nozzle opening state of FIG.

FIG. 6 is a cross-sectional view of a fluid support roll when a high thermal conductive metal member is incorporated in the nozzle closed state of FIG.

FIG. 7 is a side view showing an example of the fluid support device of the present invention.

FIG. 8 is a diagram showing an example of a fluid nozzle of the present invention,
(A) is the perspective view, (b) is sectional drawing.

FIG. 9 is a development view of a roll surface for explaining the positional relationship of nozzles formed on the roll surface.

FIG. 10 is a development view of a roll surface for explaining another example of the positional relationship of nozzles formed on the roll surface.

FIG. 11 is a perspective view of an example in which a partition plate is provided on the body supporting roll of the present invention.

FIG. 12 is a side view of a model line used in an example.

FIG. 13 is a diagram showing a measurement result of flying height in the strip width direction.

FIG. 14 is a diagram showing a thermal crown amount in the strip width direction.

[Explanation of symbols]

 1: Central roll 2: End roll 3: Roll shaft 4: Fluid ejection nozzle (nozzle) 5: Space 6: Fluid hole 7: High thermal conductive metal member 8: Partition plate 10: Fluid support roll 11: Fluid nozzle 12: Fluid Supply pipe 13: Slit 15: Back pad 20: Fluid support device 21: Heating furnace 22: Bridle device 23: Tension measuring roll 24: Tension reel

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Eiji Hirooka 5-1-1109 Shimaya, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. Kansai Works Steelmaking Works

Claims (3)

[Claims] 1. A roll for winding and carrying a strip around a roll, the roll comprising a central roll and end rolls provided at both ends and slidable in the roll axial direction. Is a structure in which a pair of fluid ejection nozzles with variable opening widths are formed spirally in the roll axial direction on the roll surface between the central roll and the end rolls by sliding. Fluid-supported roll of strip. 2. A high heat conductive metal member is incorporated on or near the surface of the roll according to claim 1, so that the central roll and the end roll are connected to each other in the axial direction of the roll. Fluid support roll. 3. A roll according to claim 1, a fluid nozzle provided in the vicinity of the roll winding start line of the strip and the back pad installed opposite to the roll surface opposite to the strip winding surface of the roll. A strip fluid support device characterized in that it is arranged.